The wreckage of an oil train derailment in Mount Carbon, W.Va., still smolders 48 hours after it crashed on Feb. 16, 2015. The derailment resulted from a broken rail that started with a crack that should have been detected, federal investigators said. Curtis TateMcClatchy

The wreckage of an oil train derailment in Mount Carbon, W.Va., still smolders 48 hours after it crashed on Feb. 16, 2015. The derailment resulted from a broken rail that started with a crack that should have been detected, federal investigators said. Curtis TateMcClatchy

The risk of a disastrous tank car explosion in a major city and preventing tragedies like last year’s fatal Amtrak derailment in Philadelphia dominated the discussion last week as the National Transportation Safety Board issued its priorities for 2016.

The NTSB sent a stern message to Congress and federal regulators about the potential consequences of delays in installing automatic-braking technology to prevent high-speed derailments and in replacing tank cars that carry volatile flammable loads.

NTSB Chairman Christopher Hart invoked the memory of a runaway train that derailed in flames in Lac-Megantic, Quebec, in 2013, killing 47 people and burning down more than 30 buildings.

“We’ve been lucky thus far that derailments involving flammable liquids in America have not yet occurred in a populated area,” Hart said as the list was revealed on Wednesday. “But an American version of Lac-Megantic could happen at any time. Instead of happening out in the middle of a wheat field, it could happen in the middle of a big city.”

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Railroads will be held to strict deadlines to install auto-braking technology and replace outmoded DOT 111 tank cars.

He said a federal requirement that railroads replace tank cars with a safer generation of tankers by 2025 was “much too long” to wait.

Board member Robert L. Sumwalt, who headed an NTSB delegation sent to the Philadelphia Amtrak crash that killed eight and injured more than 200 last May, said a congressional decision to extend the deadline for installing automatic-braking technology known as Positive Train Control was “very frustrating.”

“Every day that PTC is not in place we run the risk of another Amtrak crash,” Sumwalt said, declining to say whether Congress or the railroads deserved most of the blame. “Is it going to take another five years or another three years for it to be implemented? If that’s the case, that’s unacceptable.”

Federal Railroad Administration head Sarah Feinberg has made clear she intends to hold the railroads to strict deadlines to expedite PTC installation and get the outmoded DOT 111 tank cars replaced.

Ed Greenberg, spokesman for the American Association of Railroads, said PTC is “a full-time focus of the freight rail industry,” which already has spent $6 billion on installation.

“But the reality is this technology is not off-the shelf. It had to be developed from scratch and isn’t just about plugging in or turning on components, it is a complex step-by-step process, both in terms of safety engineering and implementation,” he said.

We have seen far too many fatalities and injuries on rail mass transit.

NTSB Chairman Christopher Hart

Hart was unsympathetic to the complexity of the challenge.

“In 2008 after a PTC preventable collision in Chatsworth, California, killed 25 people and injured more than 100, Congress passed a law mandating PTC implementation by the end of 2015,” Hart said, listing the number of accidents it could have prevented since 2008. “Now it’s 2016, and according to the 2008 law, such tragedies should be things of the past, but the railroads missed the deadline. Every PTC preventable accident death and injury on tracks and trains affected by the law will be a direct result of the missed deadline.”

Hart pointed out that Amtrak successfully met the deadline for installation of PTC in the Northeast rail corridor, but most of the big freight rail companies fell far short.

The role of the NTSB is to investigate accidents and make recommendations on safety issues to Congress and federal regulatory agencies.